不同酸体系对PM2.5中重金属测定的影响

采用3种消解体系对聚四氟乙烯滤膜采集的PM2.5样品进行消解,利用电感耦合等离子体质谱法测定样品中15种重金属元素。比较了硝酸–盐酸(A)、硝酸–过氧化氢(B)、硝酸–氢氟酸–高氯酸(C)3种体系的消解效果,分析了南京市PM2.5中重金属含量,并与文献值进行了比较。结果表明,A,B,C 3种体系测定结果的相对标准偏差的平均值分别为7.9%,9.9%和17.2%,加标回收率分别为80.5%~111.0%,87.5%~120.0%,74.1%~113.0%。C体系测定结果偏高,操作步骤繁琐,精密度差;A,B体系具有试剂用量少,精密度好,准确度高等优点,能满足环境空气PM2.5中多元素同时测定的要求。

Effects of Different Acid Digestion System on Determination of Heavy Metals in PM2.5

Three kinds of acid systems such as HNO3-HCl(A),HNO3-H2O2(B),HNO3-HF-HCLO4(C) were studied to digest the PM2.5 samples collected with PTFE filter,and 15 kinds of metal elements were determined by inductively coupled plasma-mass spectrometry (ICP-MS).The digestion efficiency,precision,and accuracy were compared,while metal elements in PM2.5 of Nanjing were analyzed and compared with historical data.The results showed that the average of relative standard deviation of A,B,C systems were 7.9％,9.9％,17.2％,and the recoveries were 80.5％-111.0％,87.5％-120.0％,74.1％-113.0％,respectively.The value of C digestion system was higher with more operating steps and poor precision.Both A and B systems can meet the requirements of rapid,efficient and accurate analysis of metal elements in PM2.5 simultaneously.